1. Field of the Invention
The present invention relates to a wire spool (or a wire reel) which is used in a binding machine or tying machine for binding together a crossing portion, an overlapped portion, or the like, of reinforcing bars with a tying wire.
2. Description of the Related Art
As this kind of binding machine, there has conventionally been known a portable binding machine, e.g., as disclosed in U.S. Pat. No. 5,505,504. With this machine, a tying wire is wound around a crossing portion, an overlapped portion, or the like, of reinforcing bars to be used in concrete structures, or the like, and the tying wire is then tightened and is finally cut. In this binding machine, the tying wire is wound around a spool (or a reel), and the spool with the tying wire wound therearound is detachably mounted on the binding machine. Once the tying wire has been used up, the blank wire spool left in the binding machine is replaced with a new wire spool with a tying wire wound therearound. As the tying wire, there is normally used a wire of a circular cross section, but one with a square cross section which has a directivity in bending and is easy in binding is also used.
The tying wire is shipped or delivered from a manufacturing factory in a state in which it is wound around the spool. Before delivering, an outer or terminal end of winding of the tying wire is fixed or adhered to the wire spool with an adhesive tape attached thereto in order to prevent the tying wire from becoming loose or unwound. The adhesive tape must have a relatively strong adhesive force which is strong enough to resist that elastic force of the tying wire which urges the tying wire to loosen from the wound state. The work of adhering this adhesive tape to secure the terminal end of the tying wire in position is troublesome and time-consuming. In addition, when the wire spool is put to use, the adhesive tape must be completely removed to prevent it from being rolled into the binding machine. Since the adhesive force of the adhesive tape is relatively strong, the peeling off of the adhesive tape is not easy. Even if the adhesive tape is removed, the adhesive agent remaining on the tying wire gets accumulated inside the binding machine. This sometimes results in a mechanical trouble of the winding machine.
In view of the above-described problems with the conventional winding machine, the present invention has an object of providing a wire spool in which the terminal end of the tying wire can be easily fixed to the wire spool or held in position and also in which the tying wire can be easily released out of the secured state.